Fabric softener and method of using



United States Patent 3,395,100 FABRHC SOFTENER AND METHOD OF USING Ralph W. Fisher, Walnut Creek, and Kirtland E. McCaleb, Oakland, Calif., assignors, by mesne assignments, to Foremost-McKesson, Inc., a corporation of Maryland No Drawing. Filed Dec. 11, 1964, Ser. No. 417,810 6 Claims. (Cl. 252-8.8)

ABSTRACT OF THE DISCLOSURE A method of softening fabrics comprising rinsing with with liquid quaternary ammonium chlorides having at least two structurally modified saturated C16 to C24 hydrocarbon radicals attached to the nitrogen and the remaining nitrogen bonds connected to lower alkyl groups. High concentrations of di(isostearyl) dimethyl ammonium chloride in alcohol are preferred.

This application relates to novel compositions of matter and to the method of using the compositions as fabric softeners. More particularly, this application relates to liquid compositions of quaternary ammonium compounds which are especially suitable as fabric softeners.

In the past, the active ingredients in fabric softeners have been solid in their natural state, and have required melting and considerable amounts of solvent in order to place them in solution or to disperse them. Solutions or dispersions are desirable for use in fabric softening in order to provide even distribution of the active ingredient throughout the fabric to be softened. If the diluent or solvent evaporates with the passage of time, there is danger of precipitation of the fabric softener from the solution, rendering it useless until redissolved. Particularly, normally solid fabric softeners tend to precipitate out and cake on the opening of the dispenser (e.g. the screw top of a container). In addition, some models of automatic washing machines have softener dispensers built in, which tend to become clogged and caked with precipitated fabric softener after a period of use. Because of the relatively high molecular weight of conventional fabric softeners, it has been difficult to obtain suitable liquid solutions of the fabric softeners. Often, fabric softeners are packaged as a dispersion of fabric softener in solvent for use in the laundry. While the concentration is adequate for use, it is much too bulky for shipping and packaging, as 95% of the product is solvent (e.g. water). Higher concentrations of conventional solid fabric softeners tend to gel or form viscous dispersions which are not easily poured. Since only small amounts of the active ingredient are required (for example 0.05 oz. for an 8 to 10 pound load of clothes) any reduction in the amount of non-active ingredients results in a substantial savings.

It is accordingly an object of this invention to provide an improved liquid fabric softener.

It is a further object of this invention to provide a fabric softening composition which is easily shipped and packaged without excessive amounts of solvent or diluent, yet is readily pourable.

It is a further object of this invention to provide a fabric softening composition which will not precipitate or cake in the dispenser.

It is another object of this invention to provide an improved method of softening fabric.

These and other objects will become apparent from the following specification and claims.

Fabric softeners have long been known in the art for treating fabrics to improve the hand or drape of the 3,395,100 Patented July 30, 1968 "ice treated fabrics. A widely used fabric softener employs a solid quaternary ammonium compound in which two long chain fatty alkyl radicals and two methyl radicals are attached to the nitrogen of the cation, and the anion is chloride.

In accordance with the present invention, we have found that a quaternary ammonium compound having a pour point below 100 F. may be advantageously used to soften fabrics. These compounds are liquid even in highly concentrated solutions without solid precipitating from the liquid. Suitable quaternary ammonium compounds include those liquid compounds in which the anion is chloride and at least two structurally modified saturated C16 to C24 hydrocarbon radicals are attached to the nitrogen, and the remaining nitrogen bonds are connected to lower alkyl groups. The term structurally modified saturated C16 to C24 hydrocarbon radical is intended to include derivatives of liquid saturated fatty acids, such as those produced as side reactions in the thermal polymerization of unsaturated long chain fatty acids.

As an example of a structurally modified acid, isostearic acid is available from Emery Industries, Inc., Cincinnati, Ohio under the designation Emery 3101D. The precise structure of Emery 3101D is not accurately known.

The structurally modified acid may be reacted with ammonia to produce the alkyl nitrile. In the case of isostearic acid, reaction with ammonia produces isostearyl nitrile which is hydrogenated to the secondary amine. The di(isostearyl) amine is reacted with methyl chloride to produce di(isostearyl) dimethyl quaternary ammonium chloride. The reaction may be illustrated as follows:

where R is a structurally modified higher saturated alkyl radical.

The quaternary ammonium compounds according to this invention differ from most quaternary ammonium compounds in that they are liquid at relatively low temperatures even in the pure state. In other respects they are similar to conventional fabric softeners composed of quaternary ammonium compounds. The unique physical property of being liquid at room temperature in or greater concentration provides a number of advantages. Thus, concentrated solutions can be used directly in softening clothes without melting as in the case of solid softeners. The typical formulations of dilute clothes softener dis persions sold for use in the home are made from solid quaternaries which must be melted and greatly diluted. Dilution of our liquid material at 75% concentration for use in home laundries may be accomplished at the time of use, thus obviating the need for packaging, shipping and storing of the dilute dispersions used heretofore. The composition of the present invention may be used at a 50%, 75 or higher level of softener content in a volatile or non-volatile solvent. Such concentrates may be introduced directly in a mechanical washer by the housewife or laundry or other users, or may be diluted to approximately 5% quaternary ammonium compound content before use. When the fabric softener of the present invention is concentrated to 50% solution, only as much is required as with the usual 5% solutions of normally solid softeners.

The present fabric softeners have a pour point below F. and are readily dissolved in small amounts of solvent (e.g. 20%) even at room temperatures. With our preferred embodiment of di(isostearyl) dimethyl quaternary ammonium chloride, we have determined the pour 3 point to be 93 F., using ASTM method D97-57. This fabric softener pours or flows sluggishly at 95 "5., but pours easily when diluted to 75% active ingredient with a suitable solvent.

Any fabric softener must be dissolved or suspended in a liquid in order to be distributed throughout the fabric to be softened so that each fiber is softened. By use of a softener having a pour point below 100 F., it is unnecessary to perform the expensive and time consuming step of placing the active ingredient in the liquid phase by melting and greatly diluting. Conventional liquid fabric softeners contain large amounts of diluent which must be packaged, shipped and stored.

A variety of solvents may be used to adjust the concentration of the liquid quaternary ammonium compounds. Monohydric and polyhydric alcohols have been found to give excellent results. Thus, hexylene glycol, a high flash point, high boiling solvent is a preferred solvent. Butyl Cellosolve may also be used. Alcohols in combination with water may also be used. For example, an isopropanol and Water mixture is a highly satisfactory solvent. Other conventional solvents which are miscible with water are suitable.

The fabric softener of this invention provides best results with cellulosic textiles, such as cotton and rayon, insofar as softening is concerned. However, synthetic textiles may also be softened. In addition, the fabric softener of this invention imparts an anti-static effect to synthetics, such as nylon and acrylic fibers.

EXAMPLE I A dispersion of 5% di(isostearyl) dimethyl quaternary ammonium chloride in water was tested in a home laundry machine operated according to the usual procedures. The softness of the washed fabrics was compared to the fabrics tested under a similar run using di-hydrogenated tallow) dimethyl quaternary ammonium chloride (Formonyte 1703) as the fabric softener. The softness of the fabrics was determined to be comparable.

EXAMPLE II A 50% solution of di(isostearyl) dimethyl quaternary ammonium chloride in hexylene glycol containing about 2% sodium acetate was tested by adding one teaspoon of the concentrated 50% solution to the final rinse in the usual cycle of a home laundry machine. The softness of the washed fabrics was comparable to that obtained by use of a 5% solution of the conventional fabric softener. A conventional softener in an equal amount of hexylene glycol is not readily dispersible in the rinse water, and therefore is ineffective in softening the fabrics washed.

EXAMPLE III A 75 solution of di(isostearyl) dimethyl quaternary ammonium chloride in isopropanol was tested in a conventional home laundry machine and determined to be comparable to the 5% solution of conventional fabric softener in improving the softness of the washed fabric.

4 EXAMPLE IV As an example of making the liquid compound, 2,000 grams of isostearic (Emery 3101D) acid was reacted with ammonia at elevated temperatures in a one gallon stirred reactor to produce isostearyl nitrile. The nitrile was distilled in a vacuum and then hydrogenated in the presence of Raney nickel as a catalyst, to produce a di(isostearyl) amine. The amine was reacted with a slight excess over theoretical of methyl chloride in a stirred reactor in the presence of sodium hydroxide and isospropanol as a solvent to produce di(isostearyl) dimethyl quaternary ammonium chloride. While hot, the sodium chloride was removed by filtration, leaving the new compound in a mixture of water and isopropanol. The new quaternary ammonium chloride is a liquid as recovered in the mixture of water and isopropanol and need not be melted, heated or treated in any other manner to avoid precipitation.

It is thus apparent that the fabric softener of the present invention satisfies a long standing need in the clothes softening field with a clothes softening ability comparable to that of other difatty dimethyl quaternary ammonium compounds but with a much lower melting point. Melting and dissolving the softener in large amounts of solvent is unnecessary.

We claim:

1. A fabric softener consisting essentially of di-iso' stearyl) dimethyl ammonium chloride having a concentration of or less and a water miscible solvent compatible with fabrics.

2. A fabric softener as in claim 1 wherein the solvent is hexylene glycol.

3. A fabric softener as in claim 1 wherein the solvent is isopropanol.

4. The method of softening fabrics comprising contacting textiles with di(isostearyl) dimethyl ammonium chloride.

5. The method of softening textiles comprising rinsing said textiles in a solution of di(isostearyl) dimethyl ammonium choride having a concentration of 75% or less in a water miscible solvent.

6. The method of imparting antistatic properties to synthetic textiles comprising rinsing the synthetic textiles in a solution of di(isostearyl) dimethyl ammonium chloride having a concentration of 75% or less in a water miscible solvent.

References Cited UNITED STATES PATENTS 3,122,502 2/1964 Waldman et a1 252-8.8

FOREIGN PATENTS 639,707 4/1962 Canada.

LEON D. ROSDOL, Primary Examiner. H. B. GUYNN, Assistant Examiner. 

